(I;m not a doctor so don't expect all this to be completely accurate.) I do agree with you, but it's because they don't know any better. every day the have people cater to them and act super nice to them and laugh when they make jokes and jus make them feel great about themselves. So, when this happens for years and years they begin to think they really are just amazing and their egos just get inflated.

Dude, people with down Syndrome are awesome. This one kid had it at my school had it. I sat down to eat lunch one day, he sat next to me and said "Hi how are you?" I was leik good, you?" He said "You're awesome!" So I said "NO, you're awesome!" and ths went on for leik 5 min. By far the best lunch in the world.